Page 12 - Biology - XII

% Frequency or Number
of quadrats (the sampling units) iin which the species is present
= ×100
Frequency Index Total number of quadrats sttudied
Materials Required
Meter scale, string, nails, hammer, measuring tape, and note pad/paper

Procedure
1. Select a good growing/cultivated fi eld/park or grassland and set the fi eld for study.

2. Follow the same method of making the quadrats. Make four quadrats of size 1 m × 1 m area each.
3. Note your observation and data in the observation table and write comments in your practical
record fi le.

Observations
Density of diff erent plant species in ___________ . (name of area studied)

S. Name of plant No. of plants in quadrats Total No. of quadrats Average
No. species plants in which species population
1 2 3 4 occurred density

1. Amaranthus 0 4 3 2 9 3 3

2. Cynodon

3.

4.

5.

Note: Number of quadrats can be increased as per requirement.

Results and Conclusion
1. From the quadrat study of the selected fi eld/park/grassland area, there are ___________ no. of
plant species.

2. The average population density of plants of ___________ species is the highest and of ___________
species is the lowest. This means that this soil (selected area) is suitable for the growth of ___________
species.
3. ___________ species of plant is dominant over other species studied.

Precautions
1. Select a good/wildly growing/cultivated area.
2. Carefully count the plants. Do not make a mistake to recount the plants. (It will give wrong results.)
3. Select one species of plant population for counting at one time.

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